Rock drill mounting



G. M. NELL May 24, 932.

ROCK DRILL MOUNTING Filed March 13, 1929 I-NVENTOR. Gusfave M /V// LQOCW A TTORNEY ator to move with the drillingmachine.

Patented May 24, 1932 UNITED STATES PATENT OFFICE GUSTAVE I. NEED, 0]DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEWYORK, N. Y., CORPORATION OF NEW JERSEY ROCK DRILL MOUNTING Applicationfiled March 18, 1829. Serial No. 346,532.

This invention relates to rock drilling ap paratus and more particularlyto the mount-V.

mgs or supports for drilling machines of the percussive type. Itdirectly concerns the conventional guide shell mounting provided with afeed screw for advancing and retracting the drilling machine.

One object of the invention is to provide an improved form of guideshell mounting arranged to have a slow forward feeding movement and arelativel quick withdrawal. Another object is to e ect the differentrates of feed automatically without requiring any change in theoperating speed of theactuating handle and without requiring the opker-11-. other object isto provide a sim 1e, compact and sturdy mechanismwhich is relatively cheap to manufacture and easy to assemble andrepair. Still other objectswill be apparent from the detaileddescription which follows. 1

I am aware that it has previously been proposed in Maxson Patent No.1614,038 to move a drilling machine along a guide shell at differentspeeds but the proposed mechanism has certain disadvantages from apractical standpoint. The speed changing mechanism therein shown issecured directly to the per cussive machine where it is subjected to allthe shocks and vibrations incident to-the operation of the percussivemotor and of the reaction of the work. The control handle being mountedon the drilling machine itself is portion of the shell mounting partlycut away and showing a percussive drill mounted thereon; v

Fig. 2 is a top plan view. partly broken away, of the shell mountingalone;

Fig. 3 is a transverse sectional view substantially on the line. 3-3 ofFig. 2;

Fig. 4 is a plan view of the gear case with fragmentary sections of theadjacent parts to Thow the ratchet and pawl arrangement; am

Fig. 5 is a right end elevational view of the gear case with the handleremoved.

Fig. 1 discloses a conventional rock drill A having a piston (not shown)which reciprocates to strike blows upon a drill steel a. Drillingmachine A is provided with slides or flanges (not shown) which engageguide grooves in a guide shell 6 and has a feed nut a in threadedengagement with a feed screw 7 rotatably supported in shell 6 so thatthe machine may be fed forwardly or rearwardly in the mounting by themanipulations of an operating handle 8. Abutments 9 and 10 supported inabutting relation on side rod extensions 6a of the shell mountingprovide thrust seats for a shoulder 7a on the feed screw to take theshock of the vibratory rec'iprocations of the rock drill which are transmitted through the feed nut a to feed screw 7.

The means providing for different relative speeds of rotation of feedscrew 7 when operating handle 8 is turned at constant speed areassociated wholly with the shell mounting and are confined to anextension 75 "of feed screw 7 projecting from end abutment member 10. Agear case 11 comprising two or more casing parts suitably securedtogether is journalled on the projecting portion 7 b of the feed screw,as shown, and has an annular series of ratchet teeth 12 and 13 on theopposite sides thereof. A spring-pressed pawl 14 slidably supported inabutment member 10 (Figs. 1, 2, and 4) engages ratchet teeth 12 and asimilar spring-pressed pawl 15 supported in handle 8 engages ratchetteeth 13; Within the gear case a small gear- 16 is splined or otherwisesecured to feed screw extension 7 b so as to rotate with the letter. Alarger gear 17 in abutting relation with gear 16 is journalled on feedscrew extension 7?) for free rotative movement and has a sleeveextension 17a projecting beyond gear case lland to this gear sleeveextension operating handle 8 is securely fastened in any suitable manneras by a clamping bolt 8a. A small gear 18 integral with or having alarger ear 19 fixedly secured thereto is journalled on a pin 20 mountedin gear case 11 in parallelism with screw extension 7?) and is soarranged that gear 18 meshes with ear 17 and gear 19 mesheswith gear 16.guitable washers 21 and a nut 22 threaded upon the extreme end of screwextension 7b prevent ear case'll and handle Sassembled thereon romcoming ofi the end of the feed screw.

The operation of the apparatus is as follows: Looking from the handleend of Fig. 1 toward drilling machine A rotation of handle 8 in acounter clock-wise direction causes pawl -to engage ratchet teeth 13with theresult that gear case 11 and the gears therewithin as a wholerotate withhandle 8 tate in the same direction. In this direction ofrotation, pawl 14 rides over ratchet teeth 12. Since the feed screw hasa right hand thread, the drilling machine A will be fed forwardly or inthe direction of the arrow shown in Fig. 1. When the rotation of handle8 is reversed or changed to a clockwise direction, pawl 15 slips overratchet teeth 13, but pawl 14 engages ratchet teeth 12 thereby holdinggear case 11 stationary. Thereupon gear 17 to which handle 8 is securedwill rotate clock-wise causing gears 18 and 19 to rotate counterclock-wise and causing gear 16 and feed screw 7 to rotate clock-wise.This makes rock drill 1 move toward the right or in the oppositedirection to the arrow in Fig. 1. The ratio of rotation betweenoperating handle 8 and feed screw 7 will depend upon the ratio of thegears 17, 18 and 19, 16. A preferred ratio is about 3 to 1 so that forone rotation of operating handle 8 in a clockwise direction, feed screw7 will rotate three times in the same direction. Thus in the form of theinvention shown, the feed screw is turned slowly in a one to one ratioby operating handle 8 in feeding drill A to the work but rotates threetimes as fast as operating handle 8 when the drill is being retractedfrom the work.

While the invention has been herein disclosed in what is now consideredto be a preferred form, it is to be understood that the invention is notlimited to the specific details thereof but covers all changes,modifications, and adaptations within the scope of the appended claims.

I claim as m invention:

1. In a gui e shell mounting for drilling machines having a feed screw,a gear case journalled on said screw, gearing within said case, a crankhandle for actuating said screw through said gearing, and means foreffecting a connection between said case and said screw whereby theyrotate together or a connection between said case and said mountingwhereby said case remains stationary relative to said screwand handle.

2. In a guide shell mounting for drilling machines havin a feed screw, agear case journalled on said screw, a gear within said case journalledon said screw and having an extension projecting beyond said case, acrank handle secured to said extension, and means operable automaticallyeither to cause said casing to rotate with said handle or to restrainthe same against rotation.

3. In a guide shell mounting for drilling machines havin a feed screw, agear case journalled on said screw, a gear within said case journalledon said screw and having an extension projecting beyond said case, acrank handle secured to said extension, and interengaging means on saidhandle and on said case for causing the latter to rotate with saidhandle when the latter is rotated in one direction.

4. In a guide shell mounting for drilling machines having a feed screw,a gear case journalled on said screw, a train of gears within said case,one of which gears is keyed to said screw and another journalledthereon, an operating handle secured to said last namedgear, and meansoperating automatically through said gear train to rotate said screw atdifferent speeds in opposite directions when said handle is rotated inopposite directions without variation in speed, said gear case rotatingwith said feed screw in one operative arrangement.

"5. In a guide shell mounting for drilling machines having a feed screw,a gear case journalled on said screw, a train of gears within said case,one of which gears is keyed to said screw and another journalledthereon, an operating handle secured to said last named gear, and meansoperating automatically through said gear train to rotate said screw atdifferent speeds in opposite directions when said handle is rotated inopposite directions without variation in speed. including alternatelyoperating clutch means between said case and said mounting and betweensaid case and said handle respectively.

6. In a guide shell mounting for drilling machines having a feed screw,a gear case journalled on said screw, a train of gears within said case,one of which gears is keyed to said screw and another journalledthereon, an operating handle secured to said lastnamed gear, and meansoperating automatically through said gear train to rotate said screw atdifferent speeds in opposite directions when said handle is rotated inopposite directions without variation in speed, including ratchet andpawl mechanism for engagement alternatively between said case on the onehand and said mounting and said handle respectively on the other.

7. In a guide shell mounting for drilling machines having a feedscrew,,a gear case journalled on said screw, a train of gears withinsaid case, one of which gears is keyed to said screw and anotherjournalled thereon, an operating handle secured to said last named gear,and means operating automatically through said gear train to rotate saidscrew at diflerent speeds in opposite directions when said handle isrotated in opposite directions without variation in speed, includingratchet teeth on opposite sides of said case, and pawl members on saidmounting and on said handle respectively for engaging said teeth.

8. In a guide shell mounting having a feed screw journalled therein andan end abutment providing a bearing for said screw, said screw having fapart extending beyond said abutment, a *gear case journalled on saidscrew extension, a gear train within said case including a gearjournalled on said exten sion and having a projecting sleeve portion. acrank handle secured to said portion of said gear, means securing saidgear case and handle upon said screw extension, clutch means betweensaid case and said abutment, and clutch means betweensaid case and saidhandle, said clutch means being operable alternately depending upon thedirection of rotation of said handle.

9. In a guide shell mounting having a feed screw journalled therein andan end abut-- ment providing a bearing for said screw, said screw havinga part extending beyond said abutment, a gear case journalled on saidscrew extension, a gear train within said case including a gearjournalled on said extension and having a projecting sleeve portion. acrank handle secured'to said portion of said gear, means for securingsaid gear case and handle upon said screw extension, an annular seriesof ratchet teeth on opposite sides of said gear case, and pawls on saidabutment and in said handle respectively for engaging said teeth. soSigned by me at Detroit, in the county of Wayne and State of Michigan,this 9th day of March, 1929.

. GUSTAVE M. NELL.

